Stability and antibacterial activity of Thymus daenensis L. essential oil nanoemulsion in mayonnaise.

BACKGROUND: There is a growing demand in the food industry for the replacement of synthetic preservatives with their natural alternatives. This has led to the development of novel methods such as encapsulation of plants essential oil with appropriate physicochemical stability, and antibacterial and organoleptic properties. This study aimed to prepare an optimal nanoemulsion of Thymus daenensis L. essential oil for use as a natural preservative in mayonnaise. RESULTS: The analysis of droplet diameter, polydispersity index, zeta potential, encapsulation rate, and intrinsic stability showed that out of nine T. daenensis essential oil-containing nanoemulsions, two preparations of A and B had high stability scores. In vitro antibacterial tests showed the adverse effect of Tween 80 volume on the antibacterial properties of nanoemulsions. One nanoemulsion (essential oil:Tween 80, ratio 1:1, 15 min sonication) was considered to be optimal based on its long-term stability and antibacterial effects on Salmonella Typhimurium, Escherichia coli, and Listeria monocytogenes. However, compared to the optimal nanoemulsion, the pure essential oil showed more antibacterial effects. The bacterial control in mayonnaise was close to equal for sodium benzoate (in maximum limit 1 g kg-1 ) and the optimal nanoemulsion (½ MIC) for 24 h. The optimal nanoemulsion achieved significantly higher sensory scores (taste, appearance, and mouthfeel) than the pure essential oil in mayonnaise (P < 0.05). CONCLUSION: The results demonstrated similar antibacterial effects for the optimal nanoemulsion and sodium benzoate. The optimal nanoemulsion, due to its desirable sensorial attributes, long-term stability, and slow release of volatile compounds, can be considered an appropriate alternative to synthetic preservatives.

The effect of short-term coenzyme Q10 supplementation and pre-cooling strategy on cardiac damage markers in elite swimmers.

Strenuous physical exercise and hyperthermia may paradoxically induce oxidative stress and adverse effects on myocardial function. The purpose of this study was to investigate the effect of 14-d coenzyme Q10 (CoQ10) supplementation and pre-cooling on serum creatine kinase-MB (CK-MB), cardiac Troponin I (cTnI), myoglobin (Mb), lactate dehydrogenase (LD), total antioxidant capacity (TAC), lipid peroxidation (LPO) and CoQ10 concentration in elite swimmers. In total, thirty-six healthy males (mean age 17 (sd 1) years) were randomly selected and divided into four groups of supplementation, supplementation with pre-cooling, pre-cooling and control. During an eighteen-session protocol in the morning and evening, subjects attended speed and endurance swimming training sessions for 5 km in each session. Blood sampling was done before (two stages) and after (two stages) administration of CoQ10 and pre-cooling. ANCOVA and repeated measurement tests with Bonferroni post hoc test were used for the statistical analysis of the data. There was no significant statistical difference among groups for the levels of CK-MB, cTnI, Mb, LD, TAC, LPO and CoQ10 at the presampling (stages 1 and 2) (P>0·05). However, pre-cooling and control groups show a significant increase in the levels of CK-MB, cTnI, Mb, LD and LPO compared with the supplementation and supplementation with pre-cooling groups in the post-sampling (stages 1 and 2) (P<0·05), except for the TAC and CoQ10. Consequently, CoQ10 supplementation prevents adverse changes of myocardial damage and oxidative stress during swimming competition phase. Meanwhile, the pre-cooling strategy individually has no desired effect on the levels of CK-MB, cTnI, Mb, LD, LPO, TAC and CoQ10.

Effect of Short-term Coenzyme Q10 Supplementation and Precooling on Serum Endogenous Antioxidant Enzymes of Elite Swimmers.

Emami, A, Tofighi, A, Asri-Rezaei, S, and Bazargani-Gilani, B. Effect of short-term coenzyme Q10 supplementation and precooling on serum endogenous antioxidant enzymes of elite swimmers. J Strength Cond Res 32(5): 1431-1439, 2018-This study aimed to investigate the effect of the use of a 2-week precooling strategy and supplementation coenzyme Q10 (CoQ10) on superoxide dismutase (SOD), catalase (CAT), and serum glutathione peroxidase (GPx) in elite, adolescent swimmers during heavy and regular trainings and recording of freestyle swimming. Thirty-six healthy males (mean ± SD; age: 17.5 ± 1.1 years, body fat content: 14.55 ± 1.75%) were randomly selected and divided into 4 groups of CoQ10 (300 mg·d), precooling (immersion in the water at 18 ± 0.5° C), supplementation with precooling, and control, each with 9 participants. During an 18-session protocol in the morning and evening, participants attended speed and endurance trainings for 5 km every session. A 3-stage blood sampling was conducted before the first recording and before and after the second recording in 800, 200, and 50 m. Repeated measurement and the Bonferroni correction were used for the statistical analyses of the data (α = 0.05). According to the results, there was no significant difference between the mean serum level of SOD, CAT, and GPx in the groups at the first stage of blood sampling (p > 0.05). At the third stage, a significant difference was observed among all groups (p < 0.05). At the second stage, precooling and control groups show a significant increase compared with the supplementation and supplementation with precooling groups (p < 0.05). As an antioxidant essential for adenosine triphosphate synthesis, CoQ10 supplementation prevented adverse changes of antioxidant enzymes during heavy trainings and swimming recording and decreased the serum level, while precooling individually increased serum level of antioxidant enzymes by itself.

Different coating application methods: Zein-based edible coating containing Heracleum persicum essential oil for shelf-life enhancement of whey-less cheese.

In this research, the efficiency of brushing (Br), dipping (Di), spraying (S), and enrobing (En) methods was compared in three concentrations of 10%, 15%, and 20% of corn zein (Z) edible coating containing 0.5% of Heracleum persicum essential oil (HEO) in the shelf-life improvement of whey-less cheese during 56 days of cold storage. The results of the photography and colorimetric (L*, a*, and b* parameters) of the samples showed that the En method in 20% of Z created a uniform, brilliant, and attractive surface on the cheese pieces compared to the other groups during the storage period, and the S, Br, and Di methods were in the next categories, respectively. The findings of the texture analysis of the samples showed that all of the treatments significantly (p ≤ .05) preserved the hardness of the cheese samples compared to the control group, and the En method containing Z 20% and HEO was the most effective treatment in preventing the hardness loss of the samples during the 56-day storage period. In all treatments, the growth of aerobic mesophilic bacteria, psychrotrophic bacteria, enterobacteriaceae, molds, and yeasts was significantly (p ≤ .05) reduced in comparison with the control sample, and the En method containing HEO and Z 20% was the most efficient in preventing the microbial growth. The rate of moisture loss, fat oxidation, and pH values of the studied samples significantly (p ≤ .05) decreased in the coated treatments containing a higher concentration of Z and HEO compared with other treatments during the storage period. According to the findings of this study, it can be concluded that the En technique containing Z20% and HEO0.5% was the most effective treatment in the shelf-life improvement of whey-less cheese during 56 days of the refrigerated storage period, and the S, Br, and Di methods were in the next ranks, respectively.

Edible film based on corn zein containing dill extract and essential oil/ß-cyclodextrin inclusion complex: Shelf life enhancement of common carp fillet.

The aim of this study was to examine the impacts of corn zein edible film (Z) fortified with dill leaves extract (DE) and encapsulated dill essential oil with ß-cyclodextrin (nDEO) on the quality of refrigerated common carp fillet. Gas chromatography/mass spectrometry (GC/MS) analysis showed that the most frequent substances of DEO were apiol (35.1%) and carvone (31.4%), respectively. Designated treatments were as follows: (1) Control (C), (2) Z, (3) Z-DE, (4) Z-DEO, (5) Z-nDEO, (6) Z-DE-DEO, and (7) Z-DE-nDEO. The physicochemical properties (thickness, moisture percent, tensile strength, elongation at break, Young's modulus, color, morphology, functional groups, and thermal resistance) of the activated films significantly improved (p ≤ .05). The total viable counts, lactic acid bacteria, Enterobacteriaceae, and psychrotrophic bacteria significantly decreased in all wrapped fillets compared to the unwrapped ones (p ≤ .05). Throughout storage period, the wrapped fillets exhibited lower changes in pH, thiobarbituric acid reactive substances, and total volatile-based nitrogen values than the unwrapped fillets. According to the sensory findings, incorporating DE and nDEO in the zein films created significantly desirable aroma and flavor in the wrapped samples during storage time (p ≤ .05). Encapsulation of DEO with ß-cyclodextrin significantly fortified preservative effects of the films in fish fillets during storage period (p ≤ .05). In conclusion, the designated composite zein edible film containing DE and nDEO can be introduced as an active edible packaging in the shelf life improvement of common carp fillets during cold storage.

Influence of extraction techniques on the efficiency of pomegranate (Punica granatum L.) peel extracts in oxidative stability of edible oils.

In this study, the effects of pomegranate (Punica granatum L.) peel extract (PPE) on the oxidative stability of soybean oil and ghee were investigated under heat conditions. Three extraction methods (immersion, ultrasound, and combined immersion-ultrasound) with eight solvents (hot water, cold water, absolute methanol, methanol 50%, absolute ethanol, ethanol 50%, absolute acetone, and acetone 50%) were used for the evaluation of the extracts. Ethanolic extract in maceration method significantly (p ≤ .05) showed the highest DPPH radical scavenging activity (95.018%), reducing power (3.981), and total phenolic content (520 mg GAE/g) compared to the other samples. Then, the effects of PPE in various concentrations (200, 400, 600, and 800 ppm) were compared to the synthetic antioxidant (Butylated hydroxytoluene 200 ppm) in the oxidative stability of soybean oil under 65°C and ghee under 55°C for 24 days with 6-day intervals, respectively. During storage period, all treatments showed a significant decrease (p ≤ .05) in peroxide value, thiobarbituric acid reactive substances, conjugated dienes value, polar compounds value, and acid value compared to the control. Except for the PPE 200 treatment, the other treatments exhibited superior efficiency to the synthetic antioxidant in a dose-dependent manner in accelerated stored edible oils. Based on the sensory analyses (flavor, odor, color, and overall acceptability), PPE significantly (p ≤ .05) preserved the sensory features compared to the control group during the entire storage time. PPE 800 ppm was the most efficient treatment in all analyses, followed by PPE 600, 400, and 200 ppm, respectively. Finally, it was concluded that PPE can be introduced as a unique alternative to synthetic antioxidants in edible oils under heating conditions.

Comparison of green and synthetic silver nanoparticles in zein-based edible films: Shelf-life study of cold-stored turkey breasts.

This study aimed to compare the effect of zein edible film containing silver nanoparticles produced by green tea leaf extract (Z-gAgNPs) with zein film containing synthetic silver nanoparticles (Z-AgNPs) on the shelf life of turkey breast during refrigerated storage. The produced silver nanoparticles were analyzed using dynamic light scattering (DLS), UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM). According to the obtained results, the green fabricated silver nanoparticles (gAgNPs) showed higher polydispersity index (PDI), stability, homogeneity, spherical shape without cavity, and lower size compared to the synthetic silver nanoparticles (AgNPs). The studied treatments were divided into four groups, including 1- control (C) (turkey breast meat without packaging), 2- Z (turkey breast meat packaged with zein film), 3- Z-AgNPs (turkey breast meat packaged with zein film containing 0.5% (w/w) of AgNPs), and 4-Z-gAgNPs (turkey breast meat packaged with zein film containing 0.5% (w/w) of gAgNPs). The treatments were analyzed for 12 days with 3-day intervals in refrigerator conditions. In general, the measurement of total viable count, total volatile basic nitrogen (TVB-N), and pH values showed that Z-gAgNPs film significantly (p ≤ .05) delayed the spoilage of the studied samples until the end of the 12th day of storage and Z-AgNPs, Z, and C treatments were in the next ranks, respectively. It is concluded that the biofabricated silver nanoparticles using green tea leaf extract have more appropriate physicochemical features and higher efficiency compared to the synthesized silver nanoparticles using chemical methods in zein edible films in improving the shelf life of the cold-stored turkey breast meat and can be introduced as a promising alternative to the plastic packaging.

Effect of extraction methods on the efficiency of sumac (Rhus coriaria L.) fruit extract in soybean oil quality during accelerated conditions.

Herbal extracts containing natural bioactive substances with numerous beneficial effects have been recently noticed as appropriate alternatives for synthetic food preservatives. In this study, we aimed to optimize the effects of different sumac (Rhus coriaria) fruit extracts (SFE) on oxidative stability of soybean oil under accelerated conditions compared to a synthetic antioxidant. Hydro-ethanolic extracts (70%) of sumac fruits were prepared by three methods of immersion (I-SFE), ultrasound (U-SFE), and microwave (M-SFE). According to the response surface methodology (RSM), 13 runs were considered in the concentrations of 0, 500, and 1000 ppm of each extract that were added to the soybean oil and stored at 60°C for a 20-day period. All of the treatments were significantly (p < .05) efficient in preventing the chemical and sensory changes of soybean oil compared to the control in the dose-dependent manner during storage period. I-SFE treatment showed the lowest peroxide value (PV) (0.000063 meq (milliequivalents) O2/kg oil), thiobarbituric acid reactive substances (TBARS) (115.06 MDA (malondialdehyde)/kg oil), and acid value (0.0169 mg KOH (potassium hydroxide)/kg oil) among the other extracts at the end of the storage period. Furthermore, I-SFE treatment earned the highest sensory scores (flavor, color, odor, and overall acceptability) of soybean oil in the range of 4-5 in comparison to the other treatments and synthetic antioxidant during storage time. According to the analysis of RSM, I-SFE in the concentration of 999.998 ppm could optimally enhance the shelf life of soybean oil for 11.3614 days under accelerated conditions. It was concluded that I-SFE with the same efficiency as synthetic antioxidants can be considered as a suitable alternative in soybean oil with various health benefits.

Gelatin-starch composite coating containing cucumber peel extract and cumin essential oil: Shelf life improvement of a cheese model.

In this study, the effects of gelatin-starch (GS) composite coating containing cucumber peel extract (CPE) and cumin essential oil (CEO) were evaluated on the shelf life enhancement of ultrafiltered (UF) cheese during 56 days of storage under refrigerated conditions. The obtained hydroethanolic CPE by the microwave method showed the best results in terms of the total phenolic content, reducing power, 2,2'-diphenyl-1-picrylhydrazyl (DPPH) activity, and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity compared to the immersion and ultrasound methods. The studied treatments were as follows: Control (C), GS, CPE, CEO, GS-CPE, GS-CEO, and GS-CPE-CEO. Scanning electron microscopic surface morphology of treated cheese samples showed the formation of a firm, integrated, flawless, and homogenous layer on the cheese slices of the GS-CPE-CEO treatment. All treatments significantly (p ≤ .05) decreased the total viable count, psychotropic bacteria, and yeast-mold population compared to the control group. Adding CEO and/or CPE to GS significantly (p ≤ .05) controlled undesirable changes in physical characteristics, such as weight, color, and hardness of the cheese slices. Throughout storage time, the coated cheese slices showed more stable chemical features in comparison to the uncoated cheese samples in terms of moisture, lipid oxidation, pH, and titratable acidity (TA). Sensory evaluation of the preparations showed that the GS coating containing CPE and CEO significantly (p ≤ .05) had pleasant effects on the sensory features (taste, odor, texture, and overall acceptability) of the cheese samples during storage time. It was concluded that composite coating of GS containing CPE and CEO could improve the microbial, physical, chemical, and sensory features of ultrafiltration (UF) cheese during refrigerated storage.

Essential Oils from Indigenous Iranian Plants: A Natural Weapon vs. Multidrug-Resistant Escherichia coli.

Aim of this study was to investigate the antimicrobial properties of herbal plant essential oils (EOs) from selected Iranian plant species such as Ferulago angulata, Zataria multiflora, Cuminum cyminum, and Mentha longifolia against antibiotic-resistant Escherichia coli (E. coli) strains. For this purpose, the Escherichia coli strains, isolated from raw cow's milk and local dairy products (yogurt, cream, whey, cheese, and confectionery products) collected from different areas of Hamedan province, Iran, were investigated for their resistance to antibiotics (i.e., streptomycin, tetracycline, gentamicin, chloramphenicol, ciprofloxacin, and cefixime). Thus, the E. coli strains were tested for their susceptibility to the above-mentioned essential oils. Regarding antibiotics, the E. coli strains were highly sensitive to ciprofloxacin. In relation to essential oils, the most effective antibacterial activity was observed with Zataria multiflora; also, the bacteria were semi-sensitive to Cuminum cyminum and Mentha longifolia essential oils. All strains were resistant to Ferulago angulata essential oil. According to the results, the essential oil of Zataria multiflora can be considered as a practical and alternative antibacterial strategy to inhibit the growth of multidrug-resistant E. coli of dairy origin.

The effects of incorporated resveratrol in edible coating based on sodium alginate on the refrigerated trout (Oncorhynchus mykiss) fillets' sensorial and physicochemical features.

The goal of this study was examining the effects of sodium alginate coating (SA) containing resveratrol (R) on enhancement rainbow trout fillets' shelf-life. Treatments of the study were as follows: control, SA, SA-R 0.001% and SA-R 0.003%. Storage of the samples was done for 15 days at 4 °C. To analyze samples, 3-day intervals were used. Compared to the uncoated trout, the values of pH, peroxide and K were significantly lower in the coated samples (p < 0.05). R enhanced the impacts of alginate on extending the samples' shelf life. Sensory analyses showed that R improved the sensory scores significantly (p < 0.05); besides, it did not show more changes on the sensory features and was invisible in the surface of samples. In the conclusion, R was suggested to be a strong alternative to synthetic antioxidants in refrigerated trout fillet in very low concentrations with many health benefits.

Effect of extraction conditions on antioxidant activity of barberry (Berberis vulgaris L.) fruit extracts.

Barberry fruit is consumed in different forms including dried fruit, juice, jam and marmalade in Iran. This fruit is also used as a food additive (flavoring and colorant) in soup and rice dishes. In present study, antioxidant activities of acetone, ethanol and water (infusion and decoction) extracts of barberry (Berberis vulgaris) fruit were investigated using 2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power methods. Total phenolic contents of the extracts were also estimated using Folin-Ciocalteu assay. In ABTS assay, acetone and ethanol extracts showed the highest radical scavenging activity, while in DPPH and reducing power methods, acetone extract and decoction exhibited the strongest antioxidant activity. Meanwhile, the antioxidant potential of water extracts increased with increasing heating time (antioxidant activity of decoction was higher than that of infusion). The highest total phenolic content was found in the acetone extract (92.75 mg GAE per g). It was concluded that the acetone extract and decoction of barberry fruit can be used as an effective natural antioxidant in food industry.

Effect of oral CoQ10 supplementation along with precooling strategy on cellular response to oxidative stress in elite swimmers.

High intensity and prolonged swimming trainings in a hot and humid environment lead to stimulated and increased production of reactive oxygen and nitrogen species (RONS). In this study, we examined the effects of 14-day coenzyme Q10 (CoQ10) supplementation and precooling strategy on the serum levels of NADPH-oxidase (NOX), hydrogen peroxide (H2O2), lactic acid (LA), creatine kinase (CK), 8-isoprostane (8-iso PGF2α), 8-hydroxy-2-deoxyguanosine (8-OHdG), aspartate aminotransferase (AST), protein carbonyls (PC), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT) in adolescent elite swimmers. Thirty-six healthy boys (mean ± SD: age = 17 ± 1 years) were randomly assigned into 4 groups: supplementation, precooling, supplementation with precooling, and control. Blood sampling was carried out pre- and post- (two stages) administration of CoQ10 along with precooling with heavy trainings. ANCOVA and repeated measurement tests with the Bonferroni post-hoc test were used for statistical analysis of data (α = 0.05). No significant difference was found among the groups for serum levels of H2O2, NADPH-oxidase, CK, LA, 8-OHdG, 8-iso PGF2α, PC, AST, ALT, and GGT at pre-sampling (P > 0.05). The precooling group showed significant increase in index levels compared to the supplementation and supplementation with precooling groups in post sampling (stages 1 and 2), respectively (P < 0.05). Oral administration of CoQ10 inhibited adverse changes in oxidative stress and muscle and liver damage indices in the competition phase of swimming. No desired effect of the precooling strategy was found on the serum levels of NADPH-oxidase, CK, LA, 8-iso PGF2α, 8-OHdG, H2O2, AST, PC, ALT, and GGT.

Physicochemical and antioxidative characteristics of Iranian pomegranate (Punica granatum L. cv. Rabbab-e-Neyriz) juice and comparison of its antioxidative activity with Zataria multiflora Boiss essential oil.

Pomegranate juice (PJ) and its products are directly used in foods due to their pleasant taste and palatability as well as preservative effects. In spite of useful effects of essential oils such as zataria multiflora Boiss essential oil (ZEO) on prolonging shelf-life of foods, their application is restricted due to their vigorous taste and aroma. In the present study, physicochemical characteristics, chemical compositions and antioxidative activities of two Iranian native plants, PJ (Rabbab-e-Neyriz cultivar) and ZEO were investigated. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power tests were used for measuring antioxidant activity. The level of total phenolic of them were also determined. Total soluble solids content, pH value, titratable acidity content and total anthocyanins content of PJ were also measured. Chemical compositions of ZEO were determined using gas-chromatography, mass-spectrometry (GC-MS). The results of antioxidative tests indicated that the ZEO was significantly more potent (p < 0.05) than PJ. Also the phenolic content in ZEO (262.52 mg per g) was significantly higher (p < 0.05) than PJ (154.90 mg per 100g). Chemical compositions analysis of ZEO indicated that its major components were carvacrol (59.17%), linalool (23.67%), trans-caryophyllene (3.07%) and carvacrol methyl ether (2.44%). In the present study, physicochemical and antioxidative characteristics of Rabbab-e-Neyriz PJ were determined for first time. It was aslo found that ZEO in comparison with PJ had higher antioxidative activity and total phenolic content.

A cytotoxicity and comparative antibacterial study on the effect of Zataria multiflora Boiss, Trachyspermum copticum essential oils, and Enrofloxacin on Aeromonas hydrophila.

OBJECTIVE: this study designed to test the antibacterial potency of enrofloxacin (ENR) and essential oils from Zataria multiflora Boiss (ZEO) and Trachyspermum copticum (TEO) on Aeromonas hydrophila. MATERIAL AND METHODS: The antibacterial potency of test compounds was determined by several methods including the inhibition zone diameter determination, microbroth dilution method and colorimetric method of MTT. The cytotoxicity of test substances was assessed on Chinook salmon (Oncorhynchus tshawytscha) embryo (CHSE-214) cells. RESULTS: RESULTS showed that ENR and tested essential oils exert antibacterial effect against A. hydrophila. Moreover, ENR exerted the most potent antibacterial effect with MIC values of 62.5 ng/ml. The natural compounds of ZEO and TEO also showed antibacterial effects with rather high MIC values of 0.315 mg/ml, and 1.25 mg/ml, respectively. None of the tested substances showed toxicity on CHSE-24 cells. CONCLUSION: It is concluded that ZEO and TEO could be applied to prevent from A. hydrophila infection. Moreover, data also suggest that MTT method could be both cost- and time-effective and accurate method of MIC determination.